“ It is undoubtedly true that the sureties on a bond of this kind are estopped from setting up, as a defense to an action for a breach of its condition, any irregularities in the form of proceeding to obtain an attachment authorized by law which would warrant its discharge upon a proper application made therefor. As the purpose of the bond is to dissolve an attachment, its due execution implies a waiver both by the defendant and his sureties of all mere irregularities. ”

“ The sureties are in a sense stakeholders. They do not claim the securities unless they are liable on the bonds, and the suit, although not brought by them, is in the nature of an interpleader to save them 'from the vexation of two proceedings on a matter which may be settled in a single suit.' The decree will bind all alike, and if the sureties are held not to be liable, it will conclude the creditors from all further proceedings against them on the bonds, and leave them free to surrender the securities to the receiver. ”

“ But however that may be, it is clear to our minds that, as it stood originally as part of section 57 after 1873, and as it stands now in the Revised Statutes, it operates as a prohibition upon all attachments against national banks under the authority of the state courts. That was evidently its purpose when first enacted, for then it was part of a section which, while providing for suits in the courts of the United States or of the state, as the plaintiff might elect, declared in express terms that if the suit was begun in a state court no attachment should issue until after judgment. ”